I do tip the maids. I once helped a friend with his small property right here in Sarasota when his wife's sister had cancer and she wanted to visit her in Israel.
It was 2 guys running a 10 unit island cottage hotel. We had to do everything. Front desk, maintanance and room service. For the 2 months I was there I truly hated the room cleaning part of the job. I was grateful that most of our guests stayed for at least 3 days. Majority stayed 1 week, as the was an island destination. I do not wish this job on my worst enemy.
I tip the maids according to the average local wages. In return I had found that any and all of my requests for service above the normal was happily provided. I always leave a little note, thanking the maid and if I needed requesting something extra. My last 2 stays at the Conrad Hotels in BKK and HKG resulyed in a nice collection of Teddy Bears and Elephants. All I did was to request an extra stuffed animal for my sister's second child and I found more of these everyday on my bed when I returned from my sightseeing. These were sold for about $10 in the lobby gift shop and I tipped around $3 depending on how much change I had that morning.